Currently that would be Intel if you want OS drivers. Along with supporting more of the OpenGL standard (i think in dev they're at 3.1 or 3.2 now from what i'v

Currently that would be Intel if you want OS drivers. Along with supporting more of the OpenGL standard (i think in dev they're at 3.1 or 3.2 now from what i've heard, which beats most of the other drivers currently) they are also doing fairly well performance wise lately too from what i've seen benchmarked. They're really come a long way and kudos to them.